One of the technology drivers behind the digital media revolution is plentiful disk space that is always getting faster and cheaper. Want more evidence of that? Look to a company called InPhase who demonstrated their Holographic Storage devices at the 2005 NAB (the television convention mecca).

I picked out some interesting quotes from an interview with InPhase's Liz Murphy in Broadcasing & Cable.

What exactly is a holographic drive?It has electronics, optical media and lasers like those used in other recording technology. And it also has a loader mechanism to feed the media into the drive. But what's different is a camera chip, which is used to record the data, and a spatial light modulator, which encodes the data.

So what's the big difference?It has a lot of very high data density in a very small form factor. A 130-mm disk will hold 300 GB vs. a 120-mm DVD disk that holds roughly 5 GB.

What's the secret?Other recording technologies write a bit at a time, but the modulator records pages of data, with each page holding 1.3 million bits in the form of pixels. And then we change the angle of the laser and write another page, and we can put hundreds of pages in the same location by doing that process.

And how cheap is it?About one-fifth the price of videotape on a per-gigabyte basis, about 50� per gigabyte. And over time, that will fall to less than 20�.

How quickly can you transfer data from a video server to the drive?We're specing a 20-MBps transfer rate. By 2009 or 2010, we expect to be at 1.6 TB of data per disk with transfer rates of 120 MBps.